Work-stacking mechanism



8 Sheets-Sheet l J. L. ROC-KERATH WORK-STACKING MECHANISM March 5, 1968Filed April 28, 196e om. Q

March 5, 1968 J, RQKERATH 3,371,631

WORK-STACKING MECHANISM Filed April 28, 1966 8 Sheets-Sheet 2 Mardi 51963 .|.Il.. RocKERArl-l 3,371,631

WORK-STACKING MECHANISM Filed April 28, 196e e sheets-sheet s March 5,1968 `.1. RocKL-:RATH 3,371,631

woRx-sTAcxING MECHANISM Filed April 28, 196e 8 sheets-sheet 4 March 5,1968 J. l.. RCKERATH woRK-s'rAcKING MECHANISM 8 Sheets-Sheet 5 FiledApri1 28; 196,6

Mmb s, 196s J. L. ROCKERATH woRK-sTAcKING MECHANISM 8 Sheets-Sheet 6Filed April 28, 1966 M w v v m March 5, 1968 J. L. RocKERATl-I 3,371,631

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29 27 To uNcuRLER AIR `1E'r5 Am CYLINDER 58a oN sTAcKER L 'ALTERNATE-f"PuLsE RELAY L Much s, 196s J. L RocKERATH WORK-STACKIG MECHANISM 8Sheets-Sheet 8 Filed April 28, 1966 IL .E whom TmmM .NN

WHEN@ whom United States Patent O 3,371,631 WRK-STACKING MECHANISM .lohnL. Rockerath, Utica, N.Y., assignor to Union Special Machine Company,Chicago, Ill., a corporation of Illinois Filed Apr. 28, 1966, Ser. No.546,026 15 Claims. (Cl. 112-2) This invention is concerned primarilywith improvements developed in relation to the construction and controlover the operation of a work-stacking mechanism. A further aspect of theinvention involves the combination of the improved work-stackingmechanism with a sewing machine adapted to apply a line of stitching tothe work-pieces which are then advanced to the work stacking mechanismfor assembly of a suitable number of such work-pieces. Moreover thecombination of the sewing machine and the work-stacking mechanism, inaccordance with the present invention, is of such a character as toenable the disposition of two such combined units adjacent to each otherand arranged at an angle of 90 to each other. By virtue of thisarrangement of two of the improved units it is possible for a singleoperator to supply work-pieces successively, rst to one unit and thenthe other. While the first unit is performing its stitching andadvancing of the work, the operator is able to introduce anotherwork-piece to the other unit. In the meantime the first unit willcomplete its operation and another work-piece may be supplied to it,while the second unit is performing its operation, and this cycle ofoperations may be repeatedly carried on over a period of time.

A feature of the invention is the provision of means for advancingsuccessive pieces of substantially flat, flexible sections of materialalong a supporting surface toward an edge thereof from which thesuccessive workpieces will hang downwardly to a position beneath thesupporting surface. The improved stacking mechanism of the presentinvention is then brought into play to pick up the overhanging portionof a section of the material and cause it to drape uniformly over thetwo sides of a stacker bar. Succeeding sections of the material aresimilarly and successively draped uniformly over the stacking bar. Bydraping the work-pieces uniformly is meant the disposition ofsubstantially equal lengths of each section of material on oppositesides of the stacking bar.

A further feature of the invention resides in the mode of operation ofthe stacking mechanism. It involves the mounting of a stacking bar onrock arms which serve to swing the bar through an arcuate path passingthrough the vertical plane in which the overhanging portion of a sectionof the material is disposed in the manner explained above. Cooperatingwith the stacking bar are two work-piece holding or clamping memberseach arranged to cooperate with the stacking bar during only a portionof the movement of the latter through the arcuate path mentioned. One ofthese clamping members serves to hold a portion of the work-pieceagainst the stacking bar on the forward side of the latter while theother serves to hold the work-piece against the stacking bar bycooperating with the opposite side of the latter. To enable the properdraping of the material over the stacking bar only one or the other ofthe clamping members is active during the major portion of the movementof the stacking bar through its arcuate path. However, for an instant,both clamping means may engage the sections of material draped over thestacking bar as the latter moves through about the central region of itsarcuate path. Thus assuming that the stacking bar moves through an arcof about 45 to 60, it will cooperate with one of the clamping or holdingmembers during about half of that 3,371,631 Patented Mar. 5, 1968 ICCarc and then with the other of the clamping or holding members duringthe other half of the arc. Provision is made for preventing the activeportion of either of the clamping members from passing to anyappreciable extent beyond the vertical plane extending through the axisabout which the stacking bar is rocked or oscillated.

A further feature of the invention involves automatic controls over theoperation of the stacking bar, so as to insure its engagement with theoverhanging section of material along a line substantially midwaybetween the forward and trailing ends of the section. As will be madeclear from the detailed description of a preferred embodiment of theinvention, to be given hereinafter, there are various adjustable meansprovided in the system for insuring smooth and uniform operation of thestacking mechanism to accomplish the specified result.

In accordance with one embodiment of the invention the stacking bar isadapted to pick up a section of material to be stacked only as thestacking bar moves in one direction along its arcuate path, namelyrearwardly from the front side of the machine, and it is then returnedidly to its original position to enable it to pick up a succeedingsection of material. However in accordance with another embodiment ofthe invention the stacking bar is adapted to pick up a section ofmaterial to be stacked as the bar swings in each direction along itsarcuate path. In this embodiment of the invention successive sections ofmaterial will be alternately stacked with the first having its face sideup and the next having its face side down.

A special feature of the preferred embodiment of the invention is theprovision of light responsive means for controlling the operation of thestacking mechanism. Thus the control over the operation of the stackingmechanism is exercised by the presence and the absence of a section ofmaterial in the path of a light beam from a light source to the lightresponsive member.

Various time delay features are incorporated in the structurecontemplated by the invention for insuring the proper timing ofoperation of the several devices and the smoothness of operation ofthose devices.

In the overall combination there is also provided as a part of thepreferred embodiment, a light responsive means for controlling theoperation of the sewing machine employed for applying a seam to eachsection of material advanced along the supporting surface. This lastmentioned light responsive means serves to control the timing andduration of the engagement of the clutch member provided in the usualtransmitter from a motor to the driving belt for the sewing machine.Provision is made in this part of the system for continuing theengagement of the clutch, and that the continued operation of the sewingmachine, for a predetermined number of cycles after the light responsivemeans would normally tend to throw out the clutch. It should bementioned here that the light responsive means in question is disposedjust in advance of the presser foot of the sewing machine, so that thedelay in throwing out the clutch is desirable to enable completion ofthe :stitching of a particular section of material after it passesbeyond the beam of light which causes said light responsive means tofunction.

With the foregoing features of the invention in mind, the preferredembodiment of the invention will now be described in greater `detail inrelation to the accompany ing drawings, in which:

FIG. 1 is a front elevational view of a unit having a supportingstructure with a sewing machine on the top of a table lboard and astacking apparatus disposed at the left and rearwardly of the sewingmachine.

FIG. 2 is a side elevational view of the unit, as seen from the left inFIG. 1;

FIG. 3 is a plan view of the unit shown in FIG. l;

FIG. 4 is a detail view, in side elevation, showing the devicesconnected with the pressurized air system embodied in the unit;

FIG. 5 is a rear view of a control box carried by the supportingstructure, and shows a plurality of valves embodied in the controlsystem;

FIG. 6 is an enlarged sectional view through a portion of the table top,taken along the line 6 6 of FIG. 3, showing means for discharging airbeneath the workpieces to uncurl the same and to facilitate movement ofthe work-piece along the table top;

FIG. 7 is an elevational view of the stacking bar and clamping orholding means in their normal, stationary position;

FIG. 8 is a view of the parts shown in FIG. 7 in the position assumedwhen the stacking bar is moving outwardly and is in the mid-position ofits outward movement;

FIG. 9 is a view similar to FIG. '7, but showing the parts on theirinward or return stroke;

FIG. 10 is a view similar to FIG. 8 but showing the relationship ofvarious elements as the stacking bar is returning to its normalstationary position;

FIG. 11 is a view, partly in cross-section, of two control valvesembodied in the system, the air cylinder which operates the stackerbeing shown schematically and not in the actual position assumed in theunit as illustrated in the earlier figures;

FIG. 12 is a circuit diagram illustrating the circuits by which varioussolenoids are operated in the course of use of the machine;

FIG. 13 is another circuit diagram showing a different arrangement ofcircuits and devices enabling the stacker bar to pick-up a work-piece onits movement in each direction along the arcuate path; and

FIG. 14 is a block diagram showing the arrangement of two of thecombined units in a manner enabling a single operator to supply work toeach of them alternately.

Referring now to FIGS. 1-7, the sewing machine designated 11 is mountedon a table top 13 carried by a supporting structure 10 arranged forvertical adjustment to maintain it in the desired position and locationin relation to the floor. A plurality of bolts 13a are provided foradjustably securing the table top 13 to the frame structure 10 at adesired elevation. A motor and clutch unit 14, commonly designated atransmitter, is secured to the underside of the table top 13 in adesired position in relation to the sewing machine. A pulley on thetransmitter 14 is connected by a belt 15 with a pulley on the main driveshaft of the sewing machine. Toward the front of the supportingstructure 10 there is xedly mounted a control box 16 having on itssurface a control panel 17 incorporating various control devices forpredetermining the operation of certain elements of the unit to 'be morefully described hereinafter. These control devices are not specificallydesignated, since their nature will be understood by persons havinggeneral'knowledge in this field. Adjacent the rear side of thesupporting structure 10, and disposed in rear of the control box 16, isan adjustable filter-lubrication-pressure regulator unit havingcomponents designated 18, 19 and 20 (FIG. 4). Air from a source underpressure (not shown) is conducted through a hose 21 to said regulatorunit 1S, 19, 20. Another hose 22 extending from said regulator unitdelivers air to a manifold 23 (FIGS. 5 and ll) from which a part of theair under pressure is delivered to the valve structure 24. Anotherportion of the air is delivered through a line 26 to the valve 25. Thesevalves 24 and 25 are mounted on the rear wall of the control box 16, asillustrated in FIG. 5. Another manifold 27, extending from the valve 24and which receives air therefrom, serves to deliver this air underpressure in two directions. Thus it is connected by a hose line 28 witha valve 30 mounted above the regulator unit 18, 19, 20, as shown in FIG.4. From the valve 30 the air is delivered through a line 33 to a tubularconnection 34 extending through the work supporting table-board 13 (FIG.6). A valve 35 provided at the upper end of hose line 33 may be adjustedto regulate the quantity of air discharged through the tube 34. At itsupper end the latter delivers the air to a bar 36 having alongitudinally extending channel provided with a series of openings inthe side Wall thereof for discharging jets of air in the directionindicated in FIG. 3. These air jets serve to uncurl and flatten outportions of the work-pieces being advanced to and through the sewingmachine. They also reduce the frictional lresistance of the work-piecesin their movement along the table top, and in fact impart a forcetending to assist in such movement.

Returning now to the manifold 27, another portion of the air deliveredto it is passed through a hose line 29 to an air cylinder 31. Thelatter, as best shown in FIG. 2, is mounted on a laterally extending armof a lever 32 which is pivotally connected at 32a (FIG. l) with aportion of the housing of the transmitter unit 14. The upper end oflever 32 is branched to cooperate with a clutch operating member 32bforming part of the transmitter unit. Each branch of the lever 32 isforked, as best shown in FIG. l, to cooperate with a bolt or stud 32Ccarried by the clutch operating member. The cylinder 31 contains apiston 31a having an axially extending stem the upper end of which isprovided with a rounded head 31b arranged to cooperate with theundersurface of the electric transmitter 14. As air is introduced intothe cylinder 31 the latter is moved downwardly in relation to the pistonto rock the lever 32 about its pivotal axis 32a and thus bring aboutengagement of the clutch. Suitable spring means, not shown, normallyurges the clutch into a disengaged position, therefore the clutch isheld engaged only so long as the cylinder 31 is maintained in itslowered position by the air introduced into the cylinder. In order toavoid a too rapid downward movement of cylinder 31, and thus a toosudden engagement of the clutch, a control valve 31C is provided in theline through which air is delivered into the cylinder. The same is truewith respect to the discharge of air from the cylinder when the clutchis to be disengaged, such air being discharged downwardly from the line29 and through the control valve 24 when the latter is shifted to itsnormal, inactive position, at a selected time determined by the movementof the workpieces through the stitching zone of the sewing machine. Aswill be explained later, in discussing the circuit.diagram of FIG. 12,the valve 24 is shifted into the position shown in FIG. 11 by theenergizing of a solenoid designated SOL-3. Such energization of thesolenoid occurs whenever work is being fed to the sewing machine andserves to interrupt a light beam from a light source to a lightresponsive element. When such light beam is interrupted upon theintroduction of the forward end of a work-piece into the stitchingregion, it will remain interrupted until the trailing end of thework-piece passes beyond a point just in advance of that at which thework is introduced to the stitching Zone.

The sewing machine utilized in connection with the form of the inventionnow being described is preferably of the character of that sold by UnionSpecial Machine Company under the style designation 61400 P. Itincorporates a feed roller, designated 12 in the accompanying drawings,which is driven from the main shaft of the machine by an eccentric driveof the character disclosed in the patent to Hayes et al. No. 2,730,977,granted J an. 17, 1956. The feed roller 12, however, is of the typedesignated by said Union Special Machine Company as No. 6l439-T. It hasa width of .250 and a diameter of /64, and it has teeth around itsperiphery extending across the width of the roller which are of thegeneral character of teeth normally provided in a feed dog. This feedroller 12 is disposed just rearwardly of the presser foot of the machineand in alinement with the line of stitch formation. Thus when thetrailing end of one workpiece leaves the stitch forming zone a threadchain is produced which is carried directly beneath the feed roller 12.The latter urges the work-piece, and then the thread chain mentioned,against a plate of the general character of that designated 149 in saidHayes et al. patent. When the feed roller is acting only on the threadchain which connects the trailing end of one work-piece with the forwardend of the next work-piece, the teeth on the feed roller tend to mashand thus greatly weaken the tensile strength of the thread chain. Thiseliminates the necessity of a thread cutter and it enables the threadchain to be readily torn apart when the sewn work-piece is grasped andmoved away from the rear side of the sewing machine by the stackingmechanism in the manner to be hereinafter more fully described.

To the top of the table board there are secured various other deviceswhich may be mentioned at this time. These include a preliminary folder37a through which the operator first passes successive work-pieces andfrom which the operator then advances the forward end of each work-pieceto a final folder 37 which serves to fold one edge of the material intothe desired form for the production of the hem to be provided therein.Beyond the delivery side of the sewing machine there is mounted on thetable top a guide member 38 which serves to direct the sewn section ofmaterial in proper relation to the stacking mechanism. It will beunderstood that the advance of the material at this time is beingperformed by the feed roller 12 and assisted by the air jets from themember 36, as previously described.

I ust in advance of the hem folder 37 there is mounted a light source 40carried by an upwardly and laterally extending arm 42. This light source'directs a beam of light downwardly toward the work table into theregion of a light responsive member 41 embedded in the table top andhaving an electrical connection, of the character to be hereinafterdescribed, to the circuit system which controls the operation of thetransmitter clutch, and thus controls the'operation of the sewingmachine.

For the purpose of indicating how the control over the operation of thesewing machine is accomplished, reference may now be had to FIG. 12 ofthe drawings. As shown in that figure there are a number of manuallyoperated switches for setting the apparatus into operation. Theseinclude switches SW-l, SW-4 and SW-3. The latter when closed serves toconnect the driving motor M of the transmitter with a suitableelectrical source adapted to supply a 220 volt three-phase alternatingcurrent to the motor for operating the same. Switches SW-1 and SW-4 areconnected into one of the three lines of the triple pole switch SW-3 andcircuits are closed therefrom to ground in the -manner to be explained.Assuming that all three of these switches have been closed, current maybe delivered from terminal HT-l to various circuits in the controlsystem. One of these circuits, designated X, extends to a startingswitch SW-6 which is normally open. A branch from line X extends to anormally closed stop switch SW-5 and from there to various other pointsin the circuitry.

When the operator has delivered a section of work to be hemmed throughthe preliminary folder 37a and then through the final folder 37 thematerial cuts off the beam of light from light source 40 to the lightresponsive element 41. This light source and light responsive elementare a part of a scanner unit of the type sold by the Farmer ElectricProducts Company under the designation PES-14. It is so adjusted that itis arranged to bring about the operation of relay R-S whenever the lightresponsive means 41 is in a dark condition, i.e. when light from lightsource 40 to the element 41 is interrupted by the passage of awork-piece therebetween.

By reference to FIG. l2 it will be noted that when the starting switchSW6 is temporarily closed, by manual operation by the operator, acircuit from X to XI will be closed to ground at GT-7 through a coil ofa relay R4. This will cause arms SPE and SPG to swing upwardly intoengagement with contacts CF and CH respectively. A circuit is thuscompleted from lines X and XIII through SPG, CH and the extension ofline XIII to and through the clutch and uncurler controlling solenoidSOL-3 to ground at GT-S. This will operate the clutch to begin theoperation of the sewing machine, and it will also bring about deliveryof air to the air jet providing member 36. It will be understood thatthese two results are achieved by the shifting of the valve stem withinthe valve unit 24 toward the left into the position shown in FIG. 1l.When the starting switch SW-6 is released by the operator, the circuitto the solenoid SOL-3 is continued to be closed by circuits undercontrol of the scanner PES-14. It will be recalled that the relay R-S ofthis scanner unit will be energized so long as the workpiece is in thepath of the beam of light from source 40 to light response means 41.Therefore the Contact SPC will be lifted -and held in engagement withcontact CD. This results in the delivery of current from HT-l throughline X to switch SW-S, further through line X to switch arm SPB of SW-4,then down to and through SPC to contact CD of relay R-5 and then throughline XII and contacts SPE and CF of relay R-4 to the coil of the latterand then to ground. Thus the relay R-4 will remain in a completedcircuit even though the starting switch SW-6 has been released by theoperator, so that the solenoid SOL-3 remains energized by the circuitthrough the lines X and XIII. The sewing machine will thus remain inoperation until the trailing end of the work-piece has passed beyond thelight beam from source 40 to light responsive means 41. Furthermore atime delay is incorporated in relay R-S so that the opening of thecircuit through the coil of the latter does not take place until thesewing machine has completed a predetermined number of cycles. Thenumber of cycles, and hence the number of stitches formed, as a resultof this delay may be varied by an appropriate adjustment of a knob ordial (not shown) provided on the scanner PES-14, to bring about thecompletion of the stitching of the section being passed through themachine, and the production of a desired number of stitches in a threadchain connecting that work-piece with the next one supplied by theoperator of the machine.

find it necessary to stop the machine before its automatic` stopping isbrought about in the manner described above, this may be done by openingthe normally closed Stop switch SW-S. This will break the circuit to thelines X which are at this time interconnected by the stop switch SW-S.It will be appreciated that such stopping of the sewing machine willnormally only become necessary when some misoperation of the sewingmachine has been noted by the operator. As soon as the inisoperation hasbeen corrected the machine may be started again by operating the startswitch SW-6. It will again re-energize relay R-4 and restore thecircuitry into its normal operation described above.

Another device incorporated in the sewing machine is a lever 43, havinga knob at its upper end positioned for easy engagement by the hand ofthe operator, this lever serving to operate the usual pressure footlifting mechanism of the sewing machine. AS best shown in FIG. 2, thelower end of lever 43 is connected with a rod 44 mounted for turningmovement through a suitable arc in brackets 44a carried by the undersideof the table top 13. Secured to rod 44 is one end of a crank arm 45which has its outer end connected with the lower end of a verticallydisposed link or rod 46. The upper end of the latter is connected with aconventional stud or arm 47 carried by a rock shaft mounted in or on theoverhanging arm of the machine, and having secured thereto adjacent itsend within the head of the sewing machine an arm connected by a linkwith the pressure bar which carries the normally downwardly spring-urgedpresser foot. Lever 43, as will be understood, will be operated by theoperator to lift the presser foot as new work-pieces are supplied to themachine, or to facilitate adjustment of the work if this should becomenecessary due to its misalincment with the stitch-forming devices.

The supporting structure is also preferably provided with a materialsupporting platform 48 on which the work to be dealt with is placed, ina position convenient for the operator to remove one work-piece afteranother to be supplied to the sewing machine. If two sewing machines areprovided at 90 angles in relation to each other, as diagrammaticallyshown in FIG. 14, the supporting structures therefor may each beprovided with a material support 48 from which the single operator willalternately remove work-pieces to supply them to the correspondingsewing machine. However one of the material supports 48 may be omitted,if desired, to enable the two units to be placed somewhat closer to eachother, and the operator will then place a selected stack of work-pieceson the one material support provided and will feed these alternately toone machine and then the other.

Turning now to the improved stacking mechanism, this is preferablymounted on an extension 10a of the supporting structure 10 (FIGS. 1 and2) which carries the table top 13, sewing machine 11, and other partspreviously described. The stacking mechanism comprises two laterallyspaced arms 50 which are preferably in the form of square tubes. Theseare rigidly secured at their lower ends to a rock shaft 51 journaled inbearings 52 carried by said frame extension 10a. The journal bearings 52are secured to the frame portion 10a by suitable strap means 53. Attheir upper ends the arms 50 are interconnected by a transverselyextending stacking bar 54. This stacking bar may consist of a round barhaving threaded, reduced diameter end portions which extend into andthrough vertical slots 55 provided in the upper ends of the arms 50. Anut cooperating with the thread portions of the stacking bar at each endthereof may be suitably tightened to retain the stacking bar in aselected position along the slots 55. If desired, the stacking bar 54,in lieu of being a solid round bar may be of hollow tubular form, asindicated at 56 in FIG. 2. This will serve to reduce the inertia forcesthat will develop during the rocking or oscillatory motion of the arms50 and stacking bar 54. When such tubular form of stacking bar isemployed, each end is plugged off with elements having a threaded axialbore therein adapted to receive the threaded ends of bolts 57 whichextend through the slots 55 from the outer sides of the arms 50 and aretightened into the threaded openings in the plugs at the ends of tube 56to retain the same rigidity. An air cylinder S8 is provided foroscillating the stacker arms and the interconnecting stacking bar tocarry the latter through a suitable arc of 50 to 60. The lower end ofthe air cylinder, as shown in FIGS. 1 and 2 is mounted for rockingmovement upon a bracket member 62 secured to the support frame 10a. Theair cylinder is of a double action type having an intake-exhaust port ateach end so that air under pressure may be introduced into and exhaustedfrom the portions of the cylinder provided at opposite sides of aslidable piston 58a within the cylinder. This piston has a rod 58bconnected therewith (see FIG. 1l), and the outer end of the latter isconnected by a member 58C with one of the arms 50. Air cylinder 58 isprovided with intake-exhaust ports at each end as mentioned above towhich air under pressure is supplied by hose lines 60 and 61, or fromwhich the air under pressure within the cylinder may be exhausted atappropriate times during the operation of the system. Check valves 59aand 59b are provided in the two ports communicating with the hose lines60 and 61, as best shown in FIG. 11. The member 58C, at the outer end ofthe piston rod, has a strap portion which cooperates with a ball shapedend of a stud 63 rigidly secured to one of the arms 50 at a pointintermediate the ends of the latter. It will be apparent from theforegoing that as air under pressure is introduced into the cylinder 58through the line 60 the piston 58a will be forced outwardly (i.e. towardthe right in FIG. 1l) land the stacker arms 50, together with thestacking bar 54, will be swung outwardly (i.e. in a counterclockwisedirection as shown in FIG. 2). During this movement of the piston 58athe hose line 61 will be connected through the valve 25 with an exhaustport e to discharge the air therefrom into the atmosphere. When thestacking bar is to be swung in the opposite direction the reversecondition will exist, and air under pressure will be introduced into theright end of the cylinder 58 (FIG. 1l) through the line 61 and air willbe exhausted from the left end of the cylinder through the hose line 60.The arrangement is such that a smooth operation of the piston and thestacking bar is insured at all times.

It will be apparent from FIGS. l, 2 and 3 that the stacking Ibar isIcarried by the arms 50 along an arcuate path, at one time in thedirection in which the work-pieces are advanced along the table top 13and at times in the opposite direction.

As -best shown in FIGS. 7-10 inclusive, the stacking bar 54 is beingrocked outwardly (Le. toward the left FIG. 2) will engage theoverhanging portion of the material to be stacked and will thus pick-upthis material. To insure retaining the work-pieces successivelypicked-up by the stacking bar 54 in a desired arrangement on thisstackmg bar, a pair of clamping or holding devices designated generallyas 72 and 73 are provided. The clamping device 72 is on the outward sideof the stacking bar (i.e. the left side as shown in FIG. 2) while theclamping device 73 is on the right or forward side of the stacking bar.Each of the clamping devices 72 and 73 comprises a generally U-shapedmember, disposed in inverted relation to the frame structure, with thegenerally downwardly extending portlons thereof having the arms of the Uspaced somewhat more closely at their lower ends than at their upperends. For this purpose the arms of the U-shaped elements are bentlaterally at an intermediate point, as |best shown in FIG. 1. The upperportions of the members 72 and 73, which serve to interconnect thegenerally vertically disposed arms or legs of the latter, are eachprovided with a central portion (72a for member 72 and 73a for member73) that is offset in relation to the end portions thereof. Thus theseupper portions of the inverted U-shaped members have bends therein atthe ends of the central portlons mentioned, which serve to position saidcentral portions at an angle of about to the axes of the generallyvertically extending arm or leg portions of the members. Preferably twoor more circular friction members, (designated 72b and 73b) are providedon the central portions of the transversely extending parts of themembers 72 and 73, and it is these friction members which engage thework-pieces at predetermined times to retaln them properly and firmly inplace on the stacking bar 54. This arrangement has been found highlydesirable, since it enables the retention of the work-pieces on thestacking bar in proper position, with no interference from the extrathickness of the work-pieces that may be present, such as along at leastone of the longitudinal edges thereof resulting from the provision ofthe hem along such edge or edges.

The lower ends of the legs of the U-shaped member 72 pass throughopenings adjacent the opposite ends of a rock shaft 74', and they areretained in a selected, adjusted position in relation to rock shaft 74by means of set screws (not shown). In a similar manner the lower endsof the inverted U-shaped member 73 are passed through openings in a-rock shaft 75 and retained thereby in a selected, adjusted position.The rock shaft 74 is rotatably journaled at its opposite ends in bearingelements 76 which are strapped to a pair of bracket assembliesdesignated generally as 78. Similarly the rock shaft 75 is journaled atits opposite ends in bearings 77 which are strapped to the -bracketassemblies 78 adjacent the opposite ends of the rock shaft. The bracketassemblies 78 are secured to the stacking bar carrying arms 50. For thispurpose each of the bracket assemblies comprises two bolts 80 extendingthrough bores in the respective stacker arms 50, these bores beinglocated above and below the rock shaft 51 which carries the stackerarms. For retaining the bearings 76 and 77 on the bracket assem- Iblies78, suitable clamp plate and strap means are provided. Thus a clampplate 78a and a stra-p lmeans 78b are affixed Iby the bolts 80 to therear side (ie. left side in FIG. 2) of each of the stacker arms 50. Onthe stems of each of the bolts 80, which protrude from the front sidesof the stacker arms (i.e. toward the right in FIG. 2) there are providedspacer sleeves 79 which are firmly held in place by nuts 70. These nutsare disposed outwardly (toward the right in FIG. 2) of a clamp plate 78eand strap means 78d for retaining the various parts in assembledrelation and for retaining the bearings 76 and 77 on the bracketassemblies 78.

As previously indicated, the work clamping or holding means carried bythe members 72 and 73 are spring urged toward the stacking bar 54.For'this purpose a torsion spring 81a coiled around the rock shaft 74has one end thereof hooked around the rock shaft 51 and the other endengaging the rear side of one of the upwardly extending legs of member72. Similarly a torsion spring 81b is coiled around the rock shaft 75and has one end hooked over the rock shaft 51 and the other end engagedwith the front side of one of the legs of the member 73. Thus it will beseen that themember 72 is urged in a clockwise direction (FIG. 2) whilemember 73 is urged in a counterclockwise direction. By virtue of theemployment of the spacer sleeves 79 between the arms 50 and the bearings77 for the rock shaft 75 the latter is spaced further away from the rockshaft 51 than are the bearings 76 for the rock shaft 74. This means thatthe work holding and clamping member 73 will be given a greater amountof longitudinal movement than will the member 72 as these members areswung upon the rocking of the stacker bar carrying arms 50. The purposeof this will be explained hereinafter.

The extent to which the members 72 and 73 may be urged by their springsin the directions indicated is limited by the provision of certain stopelements. Thus a stop element 82a, secured to the frame extension 10a,extends into the path of the lower end of member 72 so as to preventthis from rocking forwardly to a greater extent than is indicated inFIG. 7. As there shown, the element 72 has its leg portions extendingsubstantially vertically. Similarly a stop element 82h, secured to theframe extension 10a, extends into the path of the lower end of member 73so as to prevent its clockwise movement beyond the position shown inFIG. 9, which is substantially, but not quite, a truly verticalposition. The stop element 82h does not directly cooperate with a leg ofthe member 73, but is arranged to cooperate with a conical member 90adjustably secured to a leg of member 73 adjacent its lower end. Thisarrangement is such that as the member 73 is lifted and lowered, in thecourse of the swinging of the stacker bar carrying arms 50, the materialengaging elements 73b will move along a strictly vertical path as shownin FIG. 9. It has been found more important for the purpose of theinvention to insure this strictly vertical movement of the elements 73band maximum rearward movement of the member 73, under the spring force,that is the case with respect to the forward swinging of member 72. Infact it has been found desirable to have the work engaging elements 72bmove slightly further forward under spring action thana strictlyvertical line extending from the axis of the shaft 51 about which thestacker bar carrying arms 50 are rocked.

Turning now to the control system for the stacker mechanism, there isprovided, as has previously been stated, an electric light source and alight responsive element 101 (FIG. l) disposed just beyond the presserfoot of the sewing machine and forwardly of the feed roller 12. Both thelight source and the light responsive means are mounted above the tabletop and the beam of light from the light source to the light responsivemeans is reflected to the latter whenever a reflecting surface on thesewing machine, positioned at the top of the work supporting table 13,is not covered by the work being stitched. However when a work-piece isbeing fed through the sewing machine it will cover the reflectingsurface and thus cut-off the beam of light from the light source to thelight responsive element. The foregoing light and light responsive meansare connected with a scanner of the type sold by the Farmer ElectricProducts Company under the designation PE7. More particularly it is ofthe type designated PE7-98 which includes a time delay in theenergization of one of the two relays incorporated in this device.

Referring to the circuitry system diagrammatically shown in FIG. 12, thescanner mentioned above has a primary relay R-1 and a secondary relayR-2. When the solenoids provided in each of these relays are energizedby the absence of any work-piece, that would cut-off the beam of lightto the light responsive element 101, the switch arm SP-3 will be shiftedAaway from contact C-4 into engagement with contact C-5. Also the switcharm SP-6 will be lifted away from contact C47 into engagement with acontact C-8 which is not connected with any circuit. This would be thecondition of the system when it is first put into operation without anywork-piece being passed through the sewing machine. It will beunderstood that in putting the system into operation the switches SW-1,SW-4 and SW-3 will all be swung from the inactive positions shown inFIG. 12 to their closed or active positions, serving to connect thesystem into the power line which, as previously stated, is a I220 voltthree-phase source supplied for the operation of the motor M. That partof the power source used for the operation of the circuitry system beingdescribed will constitute a 220 volt 60 cycle current. None of thecircuits in the scanner control part of the system will at this time beclosed except for the circuit designated III which delivers current tothe PE7-98 scanner and from the latter to ground terminal GT-3.

Now as a work-piece is being acted upon and passes over the lightreflecting surface which directs the beam from source 100 to lightresponsive element 101 the latter will be inactivated and the two relaysR-l and R-Z will be placed in the condition illustrated in FIG. l2. Atthis time a circuit II will be completed from the line extendingdownwardly from switch SW-l to switch arm SP-3 and contact C-4 up toLITE L-1 and to ground at GT-2. This circuit includes a resistor RES-1to reduce the voltage of the current delivered to L-l. After theworkpiece has been advanced beyond the presser foot of the machine, andhas exposed the light reflecting surface adjacent the rear side of thepresser foot, the light beam will `again be reflected to the lightresponsive element 101 and bring about the operation of the relays R-land R-2.

Relay R-l will be operated immediately, but relay R-2 includes a knowntype of time delay provided in Farmer scanners of the type abovespecified, which time delay may be adjusted to provide the desirednumber of seconds before the circuit designated IV will be opened bylifting arm SP-6 away from contact C-7. Thus a solenoid designated SOL-2in a pneumatic time delay relay device designated PTR will remainenergized until the relay R-2 is operated upon expiration of its timedelay. Whenever circuit IV is closed through solenoid SOL-2 to ground atGT-4 a switch arm SP-20 will be drawn upwardly into engagement withcontact C-20. This will close a circuit V extending to the solenoidSOL-1 to ground at GT-l. It should be mentioned here that the relay PTRcontains a pneumatic time delay, illustrated schematically in FIG. 12,for retaining the switch arm SP- in engagement with contact C-20 for asuitable number of seconds after solenoid SOL-2 is de-energized upon theoperation of relay R-2.

Referring now to FIG. 11 it will be noted that energizing of solenoidSOL-1 will cause the valve 25 to assume the position there shown. Thisbrings about delivery of air from line 26 through port c to port b andthen through line 60 to the left or lower end of air cylinder 58. As haspreviously been mentioned the rate of flow of air into cylinder 58 atthis time may be controlled by appropriate adjustment of valve 59a. Asthe air is thus introduced into the cylinder the piston 5811 will beurged outwardly, toward the right in FIG. 11 but actually upwardly asthe cylinder is shown in FIGS. l and 2. The time delay involved in relayPTR after solenoid SOL-2 is deenerziged is selected to be suicient toenable completion of the operation of the piston 58b in the mannermentioned above. When circuit V is opened by the downward movement ofswitch arm SP-20, after the time delay mentioned, the solenoid SOL-1will be de-energized and the spring a will urge the valve piston withincylinder 25 toward the right (FIG. l1.) This will close off deliveryfrom line 26 into line 60 and instead cause delivery of air underpressure from line 26 into line 61 and then through adjustable controlvalve 59h into the right end of cylinder 58. Accordingly the stackingbar carrying arms 50 will be drawn inwardly again. It should bementioned here that whenever air under pressure is. delivered throughline 60 into the left end of cylinder 58 air will be discharged from theright end of said cylinder through line 61 to exhaust port e. Similarlywhen air is delivered under pressure through line 61 to the right end ofcylinder 58 air will be discharged from the left end of said cylinderthrough line 60 to exhaust port a of valve 25. It will -be understoodfrom the foregoing that when a work-piece is ready to be stacked, byexposing the light responsive element 101 to a light beam, the stackerbar 54 will `be swung outwardly and then returned with a smoothoperation and sufficiently slowly not to set up disturbing vibrationalforces and the creation of objectionable noise.

The foregoing cycle of operation of the stacking mechanism will berepeated as successive pieces of work are advanced through and beyondthe light beam between source 100 and element 101. At any time, theoperator may bring about the operation of the stacking mechanism toswing the stacking bar outwardly by closing a normally open switch SW-Z(FIG. 12). This closes a circuit designated I. Usually switch SW-2 willbe manually operated only when a desired number of work-pieces have beenstacked on the bar 54 and the operator desires to remove the collectedwork-pieces. Upon subsequent opening switch SW-Z the stacking bar willbe restored to its inward position.

Referring to FIGS. 7-10 inclusive, these illustrate the timing of themovement of the stacking bar carrying arms 50 and the cooperation of thestacking bar and the clamping or holding elements in bringing about thedesired uniform stacking of successive work-pieces. In FIG. 7 the normalposition of the various parts is shown in relation to the table top 13and the downwardly hanging portion of the material to be stacked. At theappropriate time to bring about a uniform disposition of each section ofmaterial on the stacking bar the arms 50 are swung by the operation ofpiston 58a in the manner explained. When the stacking bar reaches theposition shown in FIG. 8 it will have carried the depending portion ofthe workpiece against the clamping or holding elements 72b, and in viewof the various time delay features described above this will occur justwhen the mid-point of a particular work-piece is adapted to rest uponthe top of the stacking bar 54. As the arms 50 swing outwardly they pullaway from the stacking or holding elements 73b and provide room for theportion of the work-piece being drawn away from the table 13 to dropdownwardly without danger of becoming engaged with the elements 7311.Also during this further movement of the arms 50 into the position shownin FIG. 9 the elements 72b on the clamping or holding member 72 willrather lirmly hold the work-pieces in proper position on the stackingbar. Then as the arms 50 swing back toward the right the stacking barwill be carried against the elements 73b on the clamping or holdingmeans 73 and the latter takes over the job of insuring retention of thework-pieces properly on the stacking bar. On the continued inward strokeof the arms 50, from the position shown in FIG. 10 back to that shown inFIG. 7, the stacking bar will be disengaged from the elements 72b andthe latter will be retained in a position not to interfere with thedownward movement of the overhanging portion of the next workpiece. Byvirtue of the downward movement of the elements 73b as they are rstengaged by the work-pieces on the stacking bar, these elements serve toinsure straightening out of the material around the stacking bar andeliminate any tendency of any portions of the workpieces to extendupwardly or outwardly away from the stacking bar. It has been found thatthe construction shown and described works very effectively and simplyin bringing about the stacking of 4successive work-pieces to form adesired smooth collection of such work-pieces.

In the circuit diagram of FIG. 12 there are illustrated various lightsdesignated L-1, L-Z, and L-3. These are simply provided to give theoperator an indication of the operative condition of various elements ofthe construction. As previously explained, the light L-l indicates tothe operator when the stacking lbar is about ready to receive anothersection of material. It darkens when the relay R-1 is energized, but isrestored to its light condition when a new piece of material interceptsthe beam of light from to 101 and is approaching the position in whichit may be picked up. Light L-2 is energized upon the closing of switchSW-3 to show the operator that the motor is in operation. Light L-3 islit-up by circuit X which is completed, in the manner previouslyexplained, when the sewing machine is ready to receive a work-piece.Suitable resistances RES-1, RES-2 and RES-3 are provided in the circuitsextending to the various lights mentioned so that they may be operatedat a desired voltage.

In FIG. 13 there is shown a modified circuit, in diagrammatic form whichmay be used to enable the stacking bar to pick-up a work-piece on itsoutward swinging movement and then pick-up another work-piece on itsinward swinging movement. This will of course result in placingalternate work-pieces on the stacking bar in right side up position andthe other alternate work-pieces in right side down positon. Only thatpart of the circuitry identified with the scanner PE7-98 is shown, butit will be understood that the circuitry for controlling the operationof the sewing machine, if this in included in the overall construction,will be the same as illustrated in FIG. l2.

Current from source HT-l will be passed downwardly through switch SW-l,which will be shifted to its closed position when the system is inoperation. The circuit will be completed to the Farmer scanner PE7-98and to ground at GT-3'. Also a circuit will be completed through switcharm SP-3 to contact C-4 and line II through resistor RES-1 and LITE L-lto ground at GT-Z' whenever a work-piece is being advanced through thelight beam from 100' to 101. Thus the operator will be advised of themovement of a workpiece toward its stacking position. Thus when thework-piece is being advanced, and its forward end passes over the lightreflecting surface which directs a beam of light from source 100 to 13Alight responsive element 101', the light L-1' will be lighted. Also therelays R-l and R-2 will be de-energized and the switch arms SP-3 andSPAG will assume the positions shown in FIG. 13. Then as the trailingend of the work leaves the sewing machine and serves to expose thereflecting surface that directs the 4beam of light to element 101', therelays R-l' and R-2 will be operated, with a slight time delay in theoperation of relay R-Z. Prompt operation of relay R-l will break thecircuit II' so that the light L-l will go out. However during therelatively short time delay provided in this embodiment for theoperation of relay R-Z', the circuit IV will be completed through arelay R-3 which is an alternate pulse relay of well known construction.The circuit through the coil of this relay will be completed to groundat GT-4. This will cause the lifting of switch arm SP-40 into engagementwith contact C-41 and thus close a circuit V to solenoid SOL-1 and toground at GT-l, and will cause the outward swinging of the stacking barto pick-up the workpiece then depending downwardly from the table top13. While the relay R-3' is energized for only a very brief interval,this is enough to throw the switch arm in the direction described, andit will be retained there until another pulse is transmitted to therelay by the next workpiece passing through the lbeam of light from 100to 101. Circuit V will remain activated through solenoid SOL-1' so longas switch arm SP-40 of relay R-3 remains in engagement with contactC-41'. Thus the stacker will be held in its outward position.

When another work-piece is supplied to the apparatus and,is advancedover the light reflecting surface to cutoff the beam from light 100 tolight responsive element 101 the relays R-1' andvR-Z' will beinactivated and the parts thereof restored to the position shown in FIG.13. As the work-piece continues to be advanced by the sewing machineand/or the feed roller corresponding with that designated 12 inconnection with the first embodiment of the invention, and the trailingend of the second work-piece passes beyond the light reflecting surfacementioned, the relays R-1' and R-2' will again be activated in the samemanner as 'before with the result that another pulse will be transmittedto relay R-3. The construction of the latter is such that the switch armSP-40 will then be returned to the position shown in FIG. 13, and thecircuit V' to solenoid SOL-1' will -be de-energized. At this time thespring 25a of valve 25 will shift the position-like valve stem of thelatter toward the right from the position shown in FIG. 11, and thestacking bar will be returned forwardly to pick-up the new work-piecethat has been delivered into a position with a downwardly hangingportion in the path of the stacking bar.

It will be understood that the foregoing sequence of operations will 'berepeated as new work-pieces are advanced through the light beam. fromlight 100' to light responsive element 101', so that the rst in eachseries of alternate work-piece will be stacked right side up on thestacking bar and the second in each series of alternate work-pieces willbe stacked right side down on the stacking bar.

When the circuitry described above in relation to FIG. 13 is utilized,it will of course be necessary to change the location of the stackingbar, its carrying arms, and the clamping or holding elements. 72b and73b from that illustrated in relation to the first embodiment of theinvention. This is because of the necessity of retaining the clampingelements 73b to the right of the path of the downwardly moving portionof the next work-piece when the stacking bar is held in its outwardposition in the manner described above. This can be done by shifting thepivotal axis 51, about which the arms 50 are rocked, into a positionwithin or slightly to the right of the plane in which the downwardlyhanging portion of the material is disposed. Also the location of thestop means 82a and 82b and the form of the members 72 and 73 should besuch that the holding or clamping elements 72b and 731) will be stoppedupon the swinging of the members 72 and 73, under spring action, in aposition somewhat to the left and right, respectively, of the downwardlyhanging portion of the material to be picked up.

While certain preferred embodiments of the invention have been describedin considerable detail in the foregoing, it will be understood thatvarious changes may be made in the structure shown and described withinthe scope of the appended claims.

What is claimed is:

1. Apparatus for stacking relatively flat pieces of flexible materialwhich comprises, means providing a supporting surface along which saidpieces may be advanced, said means havingl an edge toward which saidpieces are advanced, means for advancing successive pieces of saidmaterial toward said edge and into overhanging relationship to saidedge, a stacking bar swingable in an arc below said supporting surfacepartly in a region beneath the latter and partly outwardly from saidedge thereof, said bar being maintained in substantially parallelrelation to said edge and carried through the region in which theoverhanging portions of successive workpieces are disposed, clampingmeans at opposite sides of said bar and spring urged toward the latter,means for detaining said clamping means against any substantial movementbeyond the path of the overhanging portions of the pieces opposite tothe side on which they cooperate with said bar, and means for swingingsaid bar to engage and pick-up successive pieces of the material.

2. Apparatus as set forth in claim 1 in which at least one of saidclamping means is in cooperation with said bar to retain the pieces ofmaterial in predetermined position thereon at all times during theoperation of the apparatus.

3. Apparatus as set forth in claim 1 in which said clamping means arerockably mounted to swing along only predetermined portions of thearcuate path of said stacking bar.

4. Apparatus as set forth in claim 1 in which said stacking bar iscarried by at least one arm rockable about a fixed pivot, said clampingmeans each being carried by at least one arm mounted for rockingmovement about a pivot carried by said arm which carries the stackingbar.

5. Apparatus as set forth in claim 4 in which the pivot about which saidarm carrying one of said clamping means is rocked is disposed at agreater distance from said fixed pivot than is the pivot about which thearm carrying the other of said clamping means is rocked.

6. Apparatus as set forth in claim 4 having means enabling theadjustment of the effective length of the various arms specified toadapt material pieces being stacked from time to time, which may be ofdifferent length, to be equally disposed along opposite sides of thestacking bar.

7. Apparatus as set forth in claim 4 in which each of said clampingmeans comprises a bar extending transversely from the arm which carriesthe same, said transversely extending bar of each clamping means havinga portion thereof extending in a direction toward said stacking bar andanother portion of restricted length extending parallel with saidstacking bar for cooperation therewith, thereby enabling proper stackingof pieces having different thickness in different regions.

8. In apparatus as set forth in claim 1, control means for controllingthe operation of said means for swinging said bar in response to theadvance of a piece of material being stacked to a position in which itstrailing end is at a predetermined point in its travel.

9. In apparatus as set forth in claim 8, said control means comprising asource of light and a light responsive member in the path of a beam oflight from said source Y of light.

10. Apparatus as set forth in claim 1 in which said last recited meanscomprises a piston operated by air under pressure, an-d means forcontrolling the delivery of air to and the release of air from oppositesides of said piston to enable reciprocation thereof in properly timedrelation to cause draping of the pieces of material with equal lengthsat opposite sides of said stacking bar.

11. Apparatus as set forth in claim 10 in which electrical circuits areprovided for controlling the delivery of air to and the release of airfrom opposite sides of said piston, a light beam creating source, andlight responsive means for energizing and de-energizing of said circuitsin accordance with whether said light responsive means does or `does notreceive light from said light beam creating source.

12. In apparatus as set forth in claim 1, a sewing machine mounted onsaid means providing a work supporting surface, said sewing machinehaving means for forming a line of stitching in pieces of materialsupplied thereto, and light responsive means in advance of the stitchforming means of said sewing machine for controlling the operation ofsaid sewing machine and said means for advancing successive pieces ofsaid material toward said edge.

13. In apparatus as set forth in claim 12, means manually operable bythe operator for initiating the operation of said sewing machine, andmeans for continuing the operation of said sewing machine so long as oneor more of said workpieces successively supplied by the operatorconceals said light responsive means.

14. In apparatus as set forth in claim 12, means for delaying thestopping of the operation of said sewing machine for a predeterminedselected number of operations of said sewing machine after said lightresponsive means is uncovered and exposed to light.

15. In apparatus as set forth in claim 12, said means for advancingsuccessive pieces of material comprising a feed roller driven by saidsewing machine positioned just beyond the stitch forming region of saidsewing machine, said feed roller being disposed in alinement with theline of stitching formed by said sewing machine and serving to mash andweaken the thread chain between the trailing end of one piece and theforward end of the next piece.

References Cited UNITED STATES PATENTS 3,159,122 12/1964 Hedegaard 112-23,204,590 9/1965 Rockerath et a1. 112-2 3,219,001 11/1965 Spivey et al112-2 3,228,364 1/1966 Kremer et al 112-2 3,319,851 5/1967 Horberg223-112 FOREIGN PATENTS 1,021,888 3/1966 Great Britain.

JORDAN FRANKLIN, Primary Examiner.

I. R. BOLER, Examiner.

1. APPARATUS FOR STACKING RELATIVELY FLAT PIECES OF FLEXIBLE MATERIALWHICH COMPRISES, MENAS PROVIDING A SUPPORTING SURFACE ALONG WHICH SAIDPIECES MAY BE ADVANCED, SAID MEANS HAVING AN EDGE TOWARD WHICH SAIDPIECES ARE ADVANCED, MEANS FOR ADVANCING SUCCESSIVE PIECES OF SAIDMATERIAL TOWARD SAID EDGE AND INTO OVERHANGING RELATIONSHIP TO SAIDEDGE, A STACKING BAR SWINGABLE IN AN ARC BELOW SAID SUPPORTING SURFACEPARTLY IN A REGION BENEATH THE LATTER AND PARTLY OUTWARDLY FROM SAIDEDGE THEREOF, SAID BAR BEING MAINTAINED IN SUBSTANTIALLY PARALLELRELATION TO SAID EDGE AND CARRIED THROUGH THE REGION IN WHICH THEOVERHANGING PORTIONS OF SUCCESSIVE WORKPIECES ARE DISPOSED, CLAMPINGMEANS AT OPPOSITE SIDES OF SAID BAR AND SPRING URGED TOWARD THE LATTER,MEANS FOR DETAINING SAID CLAMPING MEANS AGAINST ANY SUBSTANTIAL MOVEMENTBEYOND THE PATH OF THE OVERHANGING PORTIONS OF THE PIECES OPPOSITE TOTHE SIDE ON WHICH THEY COOPERATE WITH SAID BAR, AND MEANS FOR SWINGINGSAID BAR TO ENGAGE AND PICK-UP SUCCESSIVE PIECES OF THE MANDREL.